In handling of cryogenic liquids such as liquid hydrogen for spacecraft it is often necessary to determine the extent and seriousness of frost buildup on tanks and pipes holding the cryogenic fluid. This was accomplished herebefore by measuring a certain area of the surface of the frost, measuring the depth of the frost from within the certain area and weighing it, and then calculating the frost density. This prior technique was cumbersome because of the requirement of various tools and measuring devices which were confusing to the layman.